Some prior systems and methods provide for routing mail over networks based upon network costs agreed upon by the different nodes that make up the network. However, these systems lack stability when the transfer costs vary or fluctuate, as the nodes must agree upon the transfer costs prior to the mail being transferred. These systems also pay an excessively high cost in terms of complexity or network traffic to resolve differences in the node's views of network topology. Thus, mail may be unnecessarily delayed until the costs are agreed upon.
Other systems and methods provide for routing to multiple mail recipients that calculate a routing path based upon shortest individual paths to the recipients. These methods, however, can unnecessarily use bandwidth by sending the same mail file over multiple links to multiple recipients.
Systems that rely on agreeing at the application level about network topology are unpredictable for administrators. The present system makes the system easier to diagnose because its behavior is predictable over a wider range of network conditions. The system and method of the present invention ensure that if a message cannot reach its final destination, it will get as close as possible to the intended destination.
Accordingly, a system and method for reliably routing mail over a network to one or more recipients is desired to address one or more of these and other disadvantages.